This invention relates to engine governors used to govern the speed of an engine, such as, for example, an internal combustion engine. More particularly, this invention relates to such an engine governor which automatically increases the fuel flow to the engine during engine start up.
Mechanical engine governors have been used in a wide variety of applications in the past. One example of a prior art mechanical engine governor is shown in U.S. Pat. No. 2,646,269, assigned to the assignee of this invention. Engine governors of this type include fly-weights mounted to a shaft which is rotated at a rate proportional to the speed of the engine being governed. As the fly-weights rotate, they develop a torque on a cross shaft, which torque is an increasing function of governor speed. The torque on the cross shaft is used to control the position of an output member, which is linked to the fuel metering device of the engine. Engine speed above a preset value results in increased torque on the cross shaft and reduced fuel to the engine, and conversely engine speed below the preset value results in reduced torque on the cross shaft and increased fuel to the engine.
When such engine governors are used in automatic engine starting systems, it is often necessary to provide additional features, such as increased fuel flow during engine start up, for example. In the past, one commonly used approach to providing increased fuel during engine start up has been to mount a separate solenoid which is linked to the governor. This solenoid is energized during engine start up, and it operates to increase fuel flow above that commanded by the governor. This approach can be effective if properly implemented. However, it requires the use of an additional component, the solenoid, and it brings with it the expenses associated with the solenoid and the need to mount the solenoid in place.
The present invention is directed to an improved engine governor which automatically provides increased fuel flow to the engine during engine start up.